Hyosung Heavy Industries Corporation

Hyun Jun Kim

Byung Hwan Jeong

Hae Won Seo

Byeng Joo Byen

Yo Han Baek

A grid voltage phase detector includes: a d-q transformation unit for receiving a three-phase signal and producing a signal on d axis and a signal on q axis; a phase signal producing unit for producing a signal for phase synchronization of grid voltage from the signal on d axis and the signal on q axis; and a PR filtering unit, with a first filter having no change in magnitude and phase at a rated frequency, a second filter introducing 90° phase lead at a rated frequency, a third filter introducing 90° phase lag, and a fourth filter having no change in magnitude and phase at a rated frequency, for removing unbalanced components and harmonic components from the signal on d axis and the signal on q axis produced by the d-q transformation unit and providing the signals to the phase signal producing unit.

Grid voltage phase detector

A method for determining a scheme for converting power in every power conversion control period and converting power according to the determined scheme may comprise the steps of: calculating average power in a transformer inductor at the time of power conversion according to an SPWM scheme in a control period; calculating average power in the transformer inductor at the time of power conversion according to a DPWM scheme in a control period; and converting power according to a scheme by means of which the calculated average power of the transformer inductor is greater. Here, in the step of calculating the average power in the transformer inductor at the time of power conversion according to the DPWM scheme, it is possible to select a DPWM scheme with the maximum duty in a step-up or step-down condition given in the control period.

Power conversion method

Provided is a system for seamless power conversion in DC power distribution, the system including power conversion devices connected in parallel, and performing conversion from a AC voltage to a DC voltage between an AC power distribution network and a DC power distribution network, wherein a master power conversion device among the power conversion devices converts the AC voltage supplied from the AC power distribution network into the DC voltage including an AC voltage at a preset level, and supplies the DC voltage to a DC power distribution line of the DC power distribution network, and the remaining power conversion devices that are slave power conversion devices detect the DC voltage at the DC power distribution line in real time, and when the AC voltage is not sensed from the detected DC voltage, one of the slave power conversion devices is converted into a master power conversion device.

Growing community of inventors

Incheon, South Korea

Hyun Jun Kim